1. Field of the Invention
The field of this invention relates to a cutting disc core that is to be utilized in forming of a rotary cutting blade with the core being constructed to have a variable size center hole which is used in mounting of the cutting blade on different diameters of arbors of cutting machines.
2. Description of the Related Art
In order to manufacture a circular saw blade, there is utilized a thin, metallic, disc shaped core with the cutting surface to be located on the periphery of the core. The core includes a center hole which is used to mount the saw blade to a motor operated device (saw machine) which will cause rotation of the blade. It is intended that the blade be rotated at a high speed when in contact with the structure that is being cut, which is generally cement, marble, stone, asphalt or other hard substance.
One particular common manufacture of saw machines utilizes a rotating shaft, or arbor, that is twenty millimeters in diameter, which is 0.787 inches. This size arbor is commonly used in conjunction with smaller or hand held machines. Larger machines, which require the operator to walk behind the machine (not hand held), generally utilize a slightly larger arbor with most machines having a one inch diameter arbor. Saw blades have been constructed to be connectable to a twenty millimeter arbor or a one inch arbor. This means for an operator that is utilizing both types of machines, the operator must purchase two different blade sizes. It would be desirable to construct a blade so as to be connectable with both sizes of arbors thereby eliminating the need to purchase blades for both sizes of arbors.
A first embodiment of cutting disc core for a circular saw blade of the present invention utilizes a circular shaped body having a center hole and a continuous peripheral edge. The peripheral edge is adapted to have cutting segments mounted thereon. A plurality of slits are formed within the body located directly adjacent the hole. These slits define a generally circular configuration surrounding the hole and are located directly adjacent the hole. The slits, in essence, form a circular ring which is integrally connected to the body by a plurality of solid tabs. The circular ring can be physically removed from the body by breaking of these tabs thereby increasing the size of the center hole to permit the mounting of the body on a larger size arbor of a sawing machine.
A further embodiment of the present invention is where the first embodiment is modified by each slit having ends which define a radially outward extension with there being a tab integrally formed with the body between an extension of one slit and an extension of an adjacent slit.
A further embodiment of the present invention is where the first embodiment is modified by each tab having a radially outward portion that is smaller in width than the base of the tab which is located in alignment with the slits. Breaking of each tab is thereby to occur at the radially outward portion since the radially outward portion is weaker than the base because the radially outward portion is shorter in width than the base. This means that no portion of the broken tab will extend within the confines of the center hole.
A further embodiment of the present invention is where the basic embodiment is modified by there being at least three in number of tabs.
A second embodiment of the present invention is where there is a cutting disc core for a circular saw blade which has a center hole defined by a bushing with this bushing being removably connected to the body by a plurality of frangible connections each of which are integral with the body.
A further embodiment of the present invention is where the second embodiment is modified by each frangible connection having a base located closest to the center hole and a radially outward portion located furthest from the center hole with breaking of the frangible connection to occur at the radially outward portion.
A further embodiment of the present invention is where the second embodiment is modified by there being at least three in number of tabs.